David De Gea: Man Utd keeper has tough choice - Louis van Gaal

Manchester United manager Louis van Gaal has given the clearest indication yet that they face the prospect of losing goalkeeper David De Gea to Real Madrid.

De Gea went off with a hamstring injury during Sunday's 1-1 draw with Arsenal at Old Trafford, which makes him a doubt for United's last match of the season at Hull City next weekend - and means he may have played his final game for the club.

Real have earmarked the 24-year-old Spain international as the successor to veteran keeper Iker Casillas, and Van Gaal says he is sure to be tempted by the possibility rejoining his family and girlfriend in his homeland.

The Dutchman said he did not know if Real had made an offer, but added: "It is not easy to choose between two great clubs. We would be very happy if he stays.

"He is Spanish and his girlfriend is Spanish and he can go to another great club, so it is difficult for him to decide.

"David De Gea shall not leave us so easily because we are a great club and he wants to participate.

"He is still behind Casillas but now a Spanish club is coming."

Real dropped Casillas for their win at Espanyol on Sunday, but stand-in Keylor Navas was badly at fault as Barcelona won La Liga.

The United boss insisted he would not be doing any more to persuade De Gea, who has one more season left on his contract, to sign a new deal, explaining: "He knows everything that he has at Manchester United at this moment.

"I don't have to say anything for the benefit of Manchester United because he can feel everything. The crowd has been unbelievable. You have seen that reaction here. It has been unbelievable, for the team and for him individually.

"When he is going he is losing that because here he has a lot of credits."

What are Van Gaal's options?

Should De Gea leave, United fans saw next season's possible first-choice goalkeeper on Sunday when Victor Valdes came on to replace his injured compatriot for the final 14 minutes.

Valdes, 33, joined United as a free agent in January after leaving Barcelona at the end of his contract last summer. He signed an 18-month deal having recovered from an anterior cruciate ligament injury that had kept him sidelined since March 2014.

Valdes, who came through Barca's youth system and has been capped 20 times by Spain, shares the same agent as De Gea, Jorge Menez.

Van Gaal has previously said Valdes would not be happy as a long-term back-up, but did not single him out when discussing the De Gea situation last week, saying instead that he had a "list" of possible replacements.

Anders Lindegaard, Sam Johnstone and Ben Amos are the other senior keepers on United's books.

'Everyone wants to play for these clubs'

Victor Valdes was on the pitch for just a few minutes on Sunday before he was beaten by a Tyler Blackett own goal

Asked about De Gea's possible move, Valdes said: "Real Madrid, Barcelona, Manchester United are three of the biggest clubs in the world. Everyone in the world wants to play for these clubs.

"It's a question you would have to put to David. I cannot answer for him. I am very happy to be here. I have one more year on my contract here. Let's see what happens."

Assessing his own time at United so far, Valdes added: "It's been good, all good. My team-mates have treated me well here. The coach has treated me well. The truth is that it has all been good.

"And the fans, they are an incredible group of fans. To come on and be welcomed like that is incredible for a footballer."

Falcao future in doubt

Radamel Falcao has scored four goals during his season's loan at Manchester United

Van Gaal must also make a decision about on-loan Monaco striker Radamel Falcao, who appeared to wave goodbye to the Old Trafford crowd when he was substituted 60 minutes into another disappointing performance.

The manager said: "You know the situation with Falcao. At the end of the season, we shall decide. You have to ask him if he was waving goodbye and then quote him. You are only assuming."

Before his move to Old Trafford, the Colombia striker scored 104 goals in 139 games for Porto, Atletico Madrid and Monaco.

However, the 29-year-old who earns about £265,000-a-week at United, has managed only four goals this season, the last coming against Leicester on 31 January.

After his loan expires at the end of the season, United must decide whether to take up a £43.5m option to buy him.

Champions League qualifier 'stressful'

Van Gaal's side are guaranteed a top-four Premier League finish

Sunday's draw means that Manchester United are likely to finish fourth in the table, meaning they will face a two-legged Champions League qualifier in August.

Only the Premier League's top three sides qualify automatically for the group stages.

Van Gaal said: "We have not yet qualified for the Champions League. It is always stressful as you can meet an opponent who is halfway through a season already. It is not so easy.

"I am satisfied we have set our goal and reached that. From what I have seen of the fans, they are pleased. But I want more as manager. Next year we will fight for more."

'We must learn to finish games'

Theo Walcott's cross was deflected in off Tyler Blackett for Arsenal's late equaliser

Van Gaal also suggested that United need to find the ruthless streak of new champions Chelsea in order to challenge for next season's Premier League title.

He said: "I believe that Arsenal are maybe the best team in the league but Chelsea can finish a game.

"We were better than our opponents for one hour, and we led 1-0, but we have to finish the game. Chelsea can finish the game. We have to improve in this respect for next season.

"When you see the results we've had against the other top-six sides, they are not so bad. It's against the little clubs, who fight, defend and park the bus, that we have to be cleverer. That is what has made the difference for Chelsea this season."